My in-laws like to talk about
(a) Great hotel meals I have eaten
(b) Great conversations I have had with medical personnel
(c) Great relatives I used to have but don't any more because they're mostly dead.
And that's about it. It's useless trying to discuss anything else with them because they don't listen and once you've said your say my father-in-law will weigh in with, "I'll tell you this..." and switch the conversation back to one of the favoured topics.
(To be fair they also used to talk about how "If I had my way I'd send them all back home" but they've been cured of that.)
Ailz and I have developed a soothing fiction about how I'm a restless soul and can't sit still- which allows me to get up and leave the room when they start.